连作地黄的植株形态生理效应研究

Effect of Continuous Cropping of Rehmannia on Its Morphological and Physiological Characteristics

目的:本研究以头茬地黄为对照,通过测定地黄生育期内叶绿素含量、光合特性、根系活力及酶活性,研究连作条件下地黄形态生理特性的差异表现。方法:使用SPAD-502叶绿素测定仪测定叶绿素含量,采用LI-6400便携式光合仪测定植物光合特性,并按常规测定植物根系活力及酶系统。结果:连作地黄在生育前期其障碍效应已经发生,并伴随整个生育进程;连作地黄叶绿素含量、光合特性及根系活力都维持在较低的水平,其中处理间地黄叶绿素含量和栽后100 d的根系活力达到显著性差异。结论:连作条件下地黄光合源的不足及(块根)库容阈值的降低,可能是导致地黄连作障碍的主要原因。

Objective ： In contrast to the newly-planted plants, through measuring and analyzing the chlorophyll content, photosyn-thetic characteristics, root activity and enzyme activity of Rehmannia glutinosa in growth stages, the differentiation manifestation of R. glutinosa physiological activity mediated by continuous cropping was studied. Methods ： SPAD-502 chlorophyll meter was used to meas-ure chlorophyll content and LI-6400 portable photosynthetic apparatus to determine plant photosynthetic characteristics. Plant root vigor and enzyme system were measured following reference literature. Results： The problems of Rehmannia caused by continuous cropping had happened since the early stage of its growth period, and lasted throughout the whole growth period. Under the condition of continu- ous cropping, the chlorophyll content, photosynthetic characteristics and root activity remained at a lower level compared with the new-ly-planted plants, among which, the chlorophyll content and the root activity （100 days after planting） had significant differences. Conclusion： The insufficient photosynthesis source and the reducing of the storage capacity（ root tuber）under the condition of continu-ous cropping might be the main reasons for these problems of R. glutinosa.